In the 1990s, Weiser proposed a context-aware technology during the study of the pervasive computing. An object of the pervasive computing is to enable a computer to be aware of changes in the surrounding environment, so as to automatically take actions in accordance with the user's requirements or preset activities.
The context-aware is considered as a supporting technology for the pervasive computing. The context-aware technology enables the computers to perceive and respond to the surrounding environments. To this end, it enables the computers to collect enough information about circumstances via devices connected with them, so that appropriate reactions can be taken based on pre-determined rules.
Herein, “context” refers to information which may be used to describe current situations of an object. Although the context refers initially to location information of the user, in the last few years, the context is not limited to this, and even refers to a part of one process in which the user is involved.
For supporting applications of the context-aware, various dedicated or general-purpose context models have been proposed to select data associated with the applications, so as to improve the precision of information retrieval and take automatically reactions in response to surrounding stimulus.
A context-aware system generally has means of acquisition of the context, abstraction and comprehension of the context, application of the context, and utility evaluation and correction, as shown in FIG. 1. FIG. 1 illustrates a schematic flow chart of the context-aware in the prior art. Generally, there are three methods for acquiring the context as below.
Acquiring Explicitly: directly acquiring context information associated with the users and services by means of physical device awareness, user enquiry, user active setting and the like;
acquiring Implicitly: indirectly acquiring some context information by utilizing the known data or surrounding environments, for example, acquiring the context information regarding time according to interactive logs between the user and the system; and
acquiring Inferring: implicitly acquiring some context information which cannot be acquired through acquiring explicitly or implicitly by using statistical methods or data mining technologies.
The abstraction and comprehension of the context refers to analyzing qualitatively and quantitatively various factors impacting the users, impacting means, impacting degrees and their dependent relationships based on the collected context to form an operable model and method.
The application of the context refers to applying effective measures for the system based on the known context and a predicable potential context to provide the users with personalized services.
The utility evaluation and correction refers to evaluating effects of the application of context-aware by adopting suitable utility evaluation indexes, and finding problems based on the evaluated result to perform adaptive improvements.
Introducing the context-aware technology into the wireless communication field will endow new abilities for mobile applications. Currently, in a Long Term Evolution (LTE) system, there are preliminary awareness and applications for some context of a user equipment (UE), such as location information of the UE, a core network for positioning the users, billing, selecting Serving Gate way (SGW) and performing a Minimization of Drive Tests (MDT); and a Channel Quality Indicator (CQI) and a Buffer Status Report (BSR) reported by the UE to a base station as important parameters for allocating radio resources of uplink and downlink.